package common.wx;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Map;

import org.apache.commons.codec.digest.DigestUtils;

import common.impl.MicroBlog;

public class SignUtil {

	/**
	 * 验证签名
	 * 
	 * @param map
	 * @return
	 */
	public static boolean checkSignature(Map<String, String> map, String signKey) {
		List<String> keys = new ArrayList<String>(map.keySet());
		Collections.sort(keys);
		String prestr = "";
		String sign = null;
		for (int i = 0; i < keys.size(); i++) {
			String key = keys.get(i);
			String value = map.get(key);
			if ("sign".equals(key)) {
				sign = value;
			} else {
				if (!"".equals(prestr))
					prestr += "&";
				prestr += key + "=" + value;
			}
		}
		try {
			prestr += "&key=" + signKey;
			System.out.println("prestr = " + prestr);
			byte[] buff = prestr.getBytes("utf-8");
			String sign_me = DigestUtils.md5Hex(buff).toUpperCase();
			System.out.println("sign_me = " + sign_me);
			System.out.println("sign = " + sign);
			if (null != sign_me && sign_me.equals(sign))
				return true;
		} catch (Exception e) {
		}
		return false;
	}

	/**
	 * 验证签名 公众帐号：恒达信息
	 * 
	 * @param signature
	 * @param timestamp
	 * @param nonce
	 * @return
	 */
	public static boolean checkSignature(String token, String signature,
			String timestamp, String nonce) {
		String[] arr = new String[] { token, timestamp, nonce };
		// 将token、timestamp、nonce三个参数进行字典序排序
		Arrays.sort(arr);
		StringBuilder content = new StringBuilder();
		for (int i = 0; i < arr.length; i++) {
			content.append(arr[i]);
		}
		MessageDigest md = null;
		String tmpStr = null;

		try {
			md = MessageDigest.getInstance("SHA-1");
			// 将三个参数字符串拼接成一个字符串进行sha1加密
			byte[] digest = md.digest(content.toString().getBytes());
			tmpStr = byteToStr(digest);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}

		content = null;
		// 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
		return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;
	}

	/**
	 * 将字节数组转换为十六进制字符串
	 * 
	 * @param byteArray
	 * @return
	 */
	private static String byteToStr(byte[] byteArray) {
		String strDigest = "";
		for (int i = 0; i < byteArray.length; i++) {
			strDigest += byteToHexStr(byteArray[i]);
		}
		return strDigest;
	}

	/**
	 * 将字节转换为十六进制字符串
	 * 
	 * @param mByte
	 * @return
	 */
	private static String byteToHexStr(byte mByte) {
		char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A',
				'B', 'C', 'D', 'E', 'F' };
		char[] tempArr = new char[2];
		tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
		tempArr[1] = Digit[mByte & 0X0F];

		String s = new String(tempArr);
		return s;
	}
}
